1. Field of the Invention
The present invention relates to a localization system and a localization method capable of controlling a mobile robot, and more particularly, to a method of localizing an obstacle existing indoors using images photographed by two indoor cameras, and to a system for localizing and avoiding an object, that is, the obstacle included in the images through the method to move to a destination.
2. Description of the Related Art
In order for a mobile service robot to move indoors or outdoors, a localization technology is required to detect the location of the robot based on surrounding information, and has been variously studied. In general, the service robot obtains the surrounding information using a sensor mounted on the robot for the localization, and creates location information and a location map. In this case, although the robot is applicable to various environments, the price of the robot is increased, and a complex control structure is required in the robot for the application to the various environments. However, since the structure of an indoor space may be previously recognized, there have been studied various schemes of receiving a signal from an external device using the minimum sensors for a robot or performing localization using a specific mark. In detail, there have been studied a localization scheme of measuring the intensity of a radio frequency (RF) signal received by a terminal in, for example, the wireless local area network (WLAN), and measuring a signal transmission distance to calculate a location, a scheme of finding out the location of a robot using the difference in a transfer rate between a faster RF signal and a slower ultrasonic wave, and a localization scheme based on an artificial landmark attached to an interior and having an intrinsic pattern. However, in the above studies, since external equipment must be additionally mounted, the mounting and the maintenance of the equipment are difficult and low precision is represented with respect to localization. Accordingly, there is required a scheme of finding out and transmitting location information and an environmental map of a robot by an external device, such as a global positioning system (GPS) sensor, so that the robot may receive the location information.
In general, a surveillance camera for an indoor environment is installed in each building without a dead zone, and analyzes and processes image information because the image information is collected through a central server. When the surveillance camera installed indoors is used, the location information of an object or a robot may be found out based on environment information included in an image, a map may be created, and location information may be transmitted to a robot so that the mobile robot may move to a destination without an additional sensor. In addition, the surveillance camera may be applied to a plurality of robots. However, problems may occur in a localization scheme based on an image of the surveillance camera installed indoors as follows. First, distortion may be caused by a lens of a low-price camera, and a shadow may be made by light. In this case, to exactly obtain the image of an object, the distortion of the image must be corrected, and the shadow made by a light source must be removed. Second, the information of a region covered by an object included in a single image may not be recognized from only the single image. To find out the location and the size of the object, environment information must be complemented using information of an image photographed at a different angle and having the information of the covered region.
Patent document 1 (Korean Patent Registration No. 1203816 (issued on Nov. 15, 2012) has a limitation that a marker must be previously provided in a space where a localization system is placed in order to find out the location of the object.
Patent document 2 (Korean Unexamined Patent Publication No. 2009-0095761 (published on Sep. 10, 2009) discloses a robot vision system having a stereo panoramic camera, in which the camera is provided in the system, so that the cost of system realization is increased.